Anticoagulant therapy in high grade gliomas: a systematic review on state of the art and future perspectives

INTRODUCTION: Anticoagulation management in high-grade gliomas is a widely studied but still debated topic, since the increased thrombotic risk is accompanied by the high background rate of intralesional bleeding. Currently, the main challenge when prescribing anticoagulants to HGG patients is to balance the risk between ICH and VTE both in the perioperative period and in the postoperative follow-up during adjuvant chemo- and radiotherapic treatment. EVIDENCE ACQUISITION: A systematic review according to PRISMA-P Guidelines was performed: 12 observational studies were selected, eight retrospective and four prospective. Regarding the reviews 3 were selected, two of which analyzed bleeding complications of anticoagulation therapy and one on thrombotic events. EVIDENCE SYNTHESIS: In the selected studies, the risk of VTEs was between 4 and 33%, while in patients with VTEs subsequently subjected to anticoagulant therapy the cases of ICH ranged from 0% to 15.4%. Regarding the reviews, two meta-analyses have evaluated the incidence of ICH in patients undergoing anticoagulation therapy following thromboembolic events, they agree in quantifying the increased risk of bleeding. CONCLUSIONS: The results of our review are generally consistent in stating that the thrombotic risk is increased in patients with HGG, suggesting that more extensive antithrombotic prophylaxis could positively impact the outcome of these patients, even if currently there are no conclusive elements in indicating or contraindicating prolonged antithrombotic prophylaxis – considering that anticoagulant administration in these patients involves an increased risk of ICH. All the studies examined have considered a prolonged heparin treatment without considering the new oral anticoagulants, so further studies about this topic are needed.